from decimal import Decimal
def sq_dist(p1, p2):
	return (p1[0]-p2[0])**2+(p1[1]-p2[1])**2

def ascend(anc, anc_i):
	rec = []
	while anc[anc_i] != anc_i:
		rec.append(anc_i)
		anc_i = anc[anc_i]
	for i in rec[:-1]:
		anc[i] = anc_i
	return anc_i

def connect(anc, a, b):
	a_anc = ascend(anc,a)
	b_anc = ascend(anc,b)
	if a_anc != b_anc:
		anc[a_anc] = b_anc

def check(mid):
	anc = range(N)
	for i in xrange(N-1):
		for j in xrange(i+1,N):
			if mid >= d[i][j]:
				connect(anc,i,j)
	return ascend(anc,0) == ascend(anc,N-1)

N = int(raw_input())
xy = [map(int,raw_input().split()) for i in xrange(N)]
d = [[sq_dist(xy[i],xy[j]) for j in xrange(N)] for i in xrange(N)]
l = 0
r = sq_dist(xy[0],xy[N-1])
while r - l > 1:
	mid = (r + l) / 2
	if check(mid):
		r = mid
	else:
		l = mid
max_d = Decimal(r).sqrt()
print (int(max_d)+(max_d>int(max_d))+9) / 10 * 10